// console.log('main.js ', require('./a.js').x);
// console.log('main.js ', require('./b.js').x);

// console.log('main.js ', require('./a.js').x);
// console.log('main.js ', require('./b.js').x);
// console.log('main.js ', require('./a.js').x);
// console.log('main.js ', require('./b.js').x);

var counter = require('./lib').counter;
var incCounter = require('./lib').incCounter;

console.log(counter);  // 3
incCounter();
console.log(counter); // 3